Add error handling and fallbacks for API failures

- Add try-catch blocks to all page components
- Provide empty data fallbacks when API calls fail
- Use optional chaining for safer property access
- Log errors for debugging

Fixes 'Cannot read properties of undefined' errors.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

nextjs-app/app/compare/page.tsx

@@ -29,6 +29,7 @@ export default async function ComparePage({ searchParams }: ComparePageProps) {
   const urns = urnsParam?.split(',').map(Number).filter(Boolean) || [];
   const selectedMetric = metricParam || 'rwm_expected_pct';
 
+  try {
     // Fetch comparison data if URNs provided
     let comparisonData = null;
     if (urns.length > 0) {
@@ -44,7 +45,7 @@ export default async function ComparePage({ searchParams }: ComparePageProps) {
     const metricsResponse = await fetchMetrics();
 
     // Convert metrics object to array
-  const metricsArray = Object.values(metricsResponse.metrics);
+    const metricsArray = Object.values(metricsResponse?.metrics || {});
 
     return (
       <ComparisonView
@@ -54,4 +55,17 @@ export default async function ComparePage({ searchParams }: ComparePageProps) {
         selectedMetric={selectedMetric}
       />
     );
+  } catch (error) {
+    console.error('Error fetching data for compare page:', error);
+
+    // Return error state with empty metrics
+    return (
+      <ComparisonView
+        initialData={null}
+        initialUrns={urns}
+        metrics={[]}
+        selectedMetric={selectedMetric}
+      />
+    );
+  }
 }

nextjs-app/app/page.tsx

@@ -30,7 +30,8 @@ export default async function HomePage({ searchParams }: HomePageProps) {
   const page = parseInt(searchParams.page || '1');
   const radius = searchParams.radius ? parseInt(searchParams.radius) : undefined;
 
-  // Fetch data on server
+  // Fetch data on server with error handling
+  try {
     const [schoolsData, filtersData] = await Promise.all([
       fetchSchools({
         search: searchParams.search,
@@ -47,7 +48,18 @@ export default async function HomePage({ searchParams }: HomePageProps) {
     return (
       <HomeView
         initialSchools={schoolsData}
-      filters={filtersData.filters}
+        filters={filtersData?.filters || { local_authorities: [], school_types: [], years: [] }}
+      />
+    );
+  } catch (error) {
+    console.error('Error fetching data for home page:', error);
+
+    // Return error state with empty data
+    return (
+      <HomeView
+        initialSchools={{ schools: [], pagination: { page: 1, page_size: 50, total: 0, pages: 0 } }}
+        filters={{ local_authorities: [], school_types: [], years: [] }}
       />
     );
   }
+}

nextjs-app/app/rankings/page.tsx

@@ -30,7 +30,8 @@ export default async function RankingsPage({ searchParams }: RankingsPageProps)
   const metric = metricParam || 'rwm_expected_pct';
   const year = yearParam ? parseInt(yearParam) : undefined;
 
-  // Fetch rankings data
+  // Fetch rankings data with error handling
+  try {
     const [rankingsResponse, filtersResponse, metricsResponse] = await Promise.all([
       fetchRankings({
         metric,
@@ -43,16 +44,31 @@ export default async function RankingsPage({ searchParams }: RankingsPageProps)
     ]);
 
     // Convert metrics object to array
-  const metricsArray = Object.values(metricsResponse.metrics);
+    const metricsArray = Object.values(metricsResponse?.metrics || {});
 
     return (
       <RankingsView
-      rankings={rankingsResponse.rankings}
+        rankings={rankingsResponse?.rankings || []}
-      filters={filtersResponse.filters}
+        filters={filtersResponse?.filters || { local_authorities: [], school_types: [], years: [] }}
         metrics={metricsArray}
         selectedMetric={metric}
         selectedArea={local_authority}
         selectedYear={year}
       />
     );
+  } catch (error) {
+    console.error('Error fetching data for rankings page:', error);
+
+    // Return error state with empty data
+    return (
+      <RankingsView
+        rankings={[]}
+        filters={{ local_authorities: [], school_types: [], years: [] }}
+        metrics={[]}
+        selectedMetric={metric}
+        selectedArea={local_authority}
+        selectedYear={year}
+      />
+    );
+  }
 }